Production and separation of dipeptidyl peptidase IV from Lactococcus lactis: scale up for industrial production.

Lactococcus lactis spp. lactis and Lactococcus lactis spp. cremoris are widely used in the manufacture of fermented milk. These strains were compared for production of Dipeptidyl Peptidase IV (DPP IV) enzyme in terms of enzyme activity, specific growth rates and productivity. Lactococcus lactis spp. lactis was produced in 3 L bioreactor and scaled up to 30 and 150 L stirred tank bioreactors, and the enzyme activities were found as 110, 110 and 122 mU mL(-1), respectively. After 8 h of production, separation steps were performed. While purification fold was 127 and yield was 2.69 %, the molecular weight of the enzyme was estimated as 68 kDa. Partially purified enzyme was enteric coated with capsules and a 95.5 % of DPP IV enzyme passed into the artificial intestine. Results show that production of DPP IV enzyme by Lactococcus lactis spp. lactis strain in submerged culture is comparable with the productions by commercial strains, mostly Aspergillus, in solid state fermentations based on productivity.